Tellurium

Tellurium is hardly ever used in pure form, but these beautiful slender crystals are how it is distributed. Research is hindered by the fact that if you absorb even tiny amounts, you smell of garlic for months.

Bismuth telluride heat pump.
This is a small bismuth telluride thermoelectric heat pump. Apply a DC voltage and one side gets cold while the other side gets hot. If you attach a good heat sink and fan to the hot side, you can pump heat out of something, cooling it down. This particular device was deployed inside a USB-powered mini-fridge designed to cool one can of soda using power from your computer.Source:eBay seller goods_keeperContributor:Theodore GrayAcquired:28 March, 2009Text Updated:29 March, 2009Price: $6Size: 1.5"Purity: <20%

Pretty surface crystals.
Description supplied by the source:
This is what happens when pure tellurium is melted homogeneously and allowed to solidify in a vacuum-fairly unbelievable crystals. This piece was broken off of a different disc in order to get some insight into the internal structure-surprisingly, you can see that the top crystalline surface is basically analogous to frosting on a cake-it looks completely separate from the main melted body. Beautiful crystals though, like ice on a window.Source:Ethan CurrensContributor:Ethan CurrensAcquired:30 April, 2008Text Updated:2 May, 2008Price: AnonymousSize: 2"Purity: 99.99%

Pretty surface crystals.
Description supplied by the source:
This is what happens when pure tellurium is melted homogeneously and allowed to solidify in a vacuum-fairly unbelievable crystals. Disks like the one shown, with the incredible crystalline structure, are only as difficult to make as the largest mold or vacuum arc chamber available to you. Source:Ethan CurrensContributor:Ethan CurrensAcquired:30 April, 2008Text Updated:2 May, 2008Price: AnonymousSize: 3"Purity: 99.99%

Tiny crystal.
This is a small chip from a small bag of tellurium crystals I received from Oliver Sacks on a visit. I used it to test my very small turntable, constructed to allow accurate rotation of samples down to a couple of mm in size.Source:Oliver SacksContributor:Oliver SacksAcquired:4 August, 2004Price: DonatedSize: 0.1"Purity: 99.9%

Hollow cathode lamp.
Lamps like this are available for a very wide range of elements: Click the Sample Group link below to get a list of all the elements I have lamps like this for. They are used as light sources for atomic absorption spectrometers, which detect the presence of elements by seeing whether a sample absorbs the very specific wavelengths of light associated with the electronic transitions of the given element. The lamp uses an electric arc to stimulate the element it contains to emit its characteristic wavelengths of light: The same electronic transitions are responsible for emission and absorption, so the wavelengths are the same.
In theory, each different lamp should produce a different color of light characteristic of its element. Unfortunately, the lamps all use neon as a carrier gas: You generally have to have such a carrier gas present to maintain the electric arc. Neon emits a number of very strong orange-red lines that overwhelm the color of the specific element. In a spectrometer this is no problem because you just use a prism or diffraction grating to separate the light into a spectrum, then block out the neon lines. But it does mean that they all look pretty much the same color to the naked eye.
I've listed the price of all the lamps as $20, but that's really just a rough average: I paid varying amounts at various eBay auctions for these lamps, which list for a lot more from an instrument supplier.
(Truth in photography: These lamps all look alike. I have just duplicated a photo of one of them to use for all of them, because they really do look exactly the same regardless of what element is inside. The ones listed are all ones I actually have in the collection.)Source:eBay seller heruurContributor:Theodore GrayAcquired:24 December, 2003Price: $20Size: 8"Purity: 99.9%Sample Group:Atomic Emission Lamps

Big crystals.
I was about to bid too much for some small tellurium crystals on eBay. Fortunately Max came to my rescue, saying he had plenty and it wasn't really very expensive. So now I have a nice big chunk and it didn't cost me anything.

I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.

Sample from the Everest Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (except gases) weigh about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.

Sample from the RGB Set.
The Red Green and Blue company in England sells a very nice element collection in several versions. Max Whitby, the director of the company, very kindly donated a complete set to the periodic table table.

Small crystal, 99.999%.
Kindly donated by David Franco, who sent many elements after seeing the slashdot discussion, and this one after I sent him some Mathematica t-shirts.
This is a very fine shiny and very pure crystal. Source:David FrancoContributor:David FrancoAcquired:11 June, 2002Price: DonatedSize: 0.2"Purity: 99.999%

Himalayan sea salt.
There is a list of 84 elements that seems to pop up repeatedly in the ingredient lists of "natural" mineral products, supplements, pills, and the like. Even, it turns out, in salt. Here then is the list of minerals claimed to be found in all-natural organic Himalayan sea salt:

I wish someone would tell these people that, for example, neptunium and plutonium do not occur in nature at all, let alone in salt. Unless, I suppose, if you count nuclear fallout as a "natural" source of ingredients.
What bothers me most is what this says about the level of scientific literacy, both of the people selling the stuff, and the people buying it. Does no one actually read the list? Or do they read it an not realize how preposterous it is? It's enough to make you despair for the future of mankind.
Pretty salt, though.Source:eBay seller saltwondersContributor:Theodore GrayAcquired:28 March, 2009Text Updated:4 April, 2009Price: $15Size: 0.25"Composition:NaClSbCsDyErEuGdHfHoInLaLuNdPrSmScThTlTeTbTmYbY

Insane mineral capsules.
These minerals capsules are called "Immune Boost 77", from Morningstar Minerals. They are either being incredibly honest, or they really don't understand what they're saying when they list what amounts to nearly the entire periodic table on the label, as the "trace minerals" they contain.

Some of them are just silly, like thulium, which has absolutely no biological function. Others are a bit scarier, like thallium and thorium that are deadly poisons, and tellurium, which makes you smell of rotten onions for weeks.

Basically what they've done is list everything that occurs in even trace amounts in mixed monazite sand, which is kind of what the stuff inside looks like. The only reason they aren't seriously harmful (I assume) is that most of these are not actually present in any meaningful quantity.

My attention is drawn to these and other similar mineral supplements every time I decide to see if anything interesting has popped up on eBay for one or another of the obscure rare earths. Generally speaking if you search eBay for those guys you get very little of interest unless you turn on the option to search the text of the item description as well as the titles. Then you get lots of trace mineral supplements that one can only hope don't actually contain them.

BiTeEr lump.
This is a roughly bullet-shaped lump of what is described on the envelope it came in as about half Bi, half Te, and a trace of Er. Actually the exact percentages are given, but in deference to whoever discarded this item I'm not listing them, in case they represent some kind of secret formula for making really good lumps of metal, or something. Ethan seems to have gotten into a batch of strange tellurium compounds someone at his university was throwing away: I'm going to be listing more of them soon.
Reader Anders Mikkelsen suggests that this alloy may have been used in research into Peltier junctions.Source:Ethan CurrensContributor:Ethan CurrensAcquired:18 March, 2007Text Updated:28 March, 2009Price: DonatedSize: 1"Composition:BiTeEr